Polyolefin dispersion technology used for porous substrates

1. A method of forming an article comprising:

applying an aqueous dispersion to a porous substrate, wherein the aqueous dispersion comprises

a thermoplastic polymer,

a dispersing agent,

a neutralizing agent; and

water; and

selecting a desired Moisture Vapor Transmission Rate (MVTR) of the article and removing at least a portion of the water employing a drying process comprising exposing the dispersion-coated porous substrate to one or more temperatures for times sufficient to achieve the selected MVTR;

wherein the article formed is breathable and has a MVTR of at least about 300 g/m 2 per 24 hours measured using ASTM Standard E96-80, upright cup method.

2. The method of claim 1 , wherein the porous substrate has an average pore size of from about 50 micrometers to about 150 micrometers.

3. The method of claim 1 , wherein the porous substrate is a nonwoven substrate, and the application of the aqueous dispersion to the nonwoven substrate is integrated into a manufacturing line of the nonwoven substrate at a line speed substantially equal to a line speed of production of the nonwoven.

4. The method of claim 3 , wherein the applying the aqueous dispersion comprises curtain coating the non-woven substrate, and wherein the line speed of production of the nonwoven substrate ranges from 100 m/min to 1100 m/min.

5. The method of claim 1 , wherein the thermoplastic polymer comprises a polyolefin.

6. The method of claim 1 , wherein the dispersing agent comprises at least one ethylene/carboxylic acid copolymer.

7. The method of claim 6 , wherein the ethylene/carboxylic acid copolymer is an ethylene/acrylic acid copolymer.

8. The method of claim 1 , comprising a dispersed particulate having an average volume diameter size of 0.1 to about 5 micrometers.

9. The method of claim 1 , wherein the neutralizing agent is ammonium hydroxide.

10. The method of claim 1 , further comprising applying multiple layers of dispersions.